This application relates to the art of article stacking and, more particularly, to stacking of generally flat articles. The invention is particularly applicable for use in stacking newspapers or the like and will be particularly described with respect thereto. However, it will be appreciated that certain aspects of the invention may be used in apparatus of other types.
Newspapers are discharged from modern presses in folded and overlapped relationship moving generally flatways is a continuous stream. The papers are received and stacked in stacker apparatus which must operate at very high speeds. The design and operation of the stacker apparatus is complicated due to the fact that newspapers and other similar flat articles vary in size, weight and conformity, and are not dimensionally stable. Movement of the papers is also influenced by rather subtle forces including air, static electricity and friction. Papers weighing only a few ounces or over one pound apiece must be handled at rates exceeding 20 per second, and at instantaneous rates exceeding 60 per second, in a continuous stream or flow often exceeding 1000 pounds per minute. This stream must be separated into accurately counted stacks at rates at least up to one stack per second. In normal operation, the continuous rapidly moving stream of papers places pressure on the stacker to perform flawlessly at extremely high stacking rates, and the stacker apparatus cannot skip or pause without instantly jamming itself, or jamming other related machinery.
Existing stacker apparatus has become very complicated in an attempt to achieve extremely high production speeds. It would be desirable to have a stacker apparatus which was characterized by its relative simplicity and high speed operation.